A Saiyans Revenge

In a world, where three species live. Devils, Angels, and Fallen Angels. But there was one more. Saiyans.
The three factions had a war that ended with neither side winning, but the devils weren't ready to lose. They knew the Saiyans had power that could rival gods, but more than 90% died out. The only ones left that the devils knew of, were a family of five. The father of this family had achieved the power of super saiyan, one child of age was still in training when the devil king asked for his alliance, but the father refused.
The devil king didn't take to kindly to that, and lured the entire family out, where the devil king's little sister would kill them and take the power for themselves.
How will time play out? How will the other factions respond? How many more must die?
Only time will tell.